Thienopyridine-derivatives (ticlopidine, clopidogrel, and prasugrel) are the primary antiplatelet agents. Thrombotic thrombocytopenic purpura (TTP) is a rare drug-associated syndrome, with the thienopyridines being the most common drugs implicated in this syndrome. We reviewed 20 years of information on clinical, epidemiologic, and laboratory findings for thienopyridine-associated TTP. Four, 11, and 11 cases of thienopyridine-associated TTP were reported in the first year of marketing of ticlopidine (1989), clopidogrel (1998), and prasugrel (2010), respectively. As of 2011, the FDA received reports of 97 ticlopidine-, 197 clopidogrel-, and 14 prasugrel-associated TTP cases. Severe deficiency of ADAMTS-13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) was present in 80% and antibodies to 100% of these TTP patients on ticlopidine, 0% of the patients with clopidogrel-associated TTP (p < 0.05), and an unknown percentage of patients with prasugrel-associated TTP. TTP is associated with use of each of the three thienopyridines, although the mechanistic pathways may differ.
thrombotic thrombocytopenic purpura; ticlopidine; clopidogrel; prasugrel; adverse event
thrombotic thrombocytopenic purpura; ticlopidine; ADAMTS13; ADAMTS13 inhibitor; Japan
Rationale and Objectives
The Food and Drug Administration recommends renal function estimation using laboratory testing for patients at risk for chronically reduced kidney function before the administration of gadolinium-based contrast agents (GBCAs). Point-of-care (POC) estimated glomerular filtration rate (eGFR) testing was added to the pre-magnetic resonance (MR) questionnaire at our institution in June 2008 for all patients undergoing a contrast-enhanced MR exam. This study was done to evaluate the effectiveness of a pre-MR screening questionnaire about kidney disease and to assess POC eGFR detection of additional patients at risk for nephrogenic systemic fibrosis.
Materials and Methods
This retrospective study was approved by our institutional review board and determined to be Health Insurance Portability and Accountability Act compliant. Medical records, laboratory data, and pre-MR questionnaires of all patients who presented for contrast-enhanced MR scans during October 2008 were reviewed. The National Kidney Disease Education Program isotope-dilution mass spectrometry-traceable Modification of Diet in Renal Disease equation was used to calculate eGFRs using the POC creatinine laboratory value, age, race, and gender. Sensitivity and specificity were calculated using 2 × 2 tables, and 95% confidence intervals were calculated with exact binomial confidence intervals.
A total of 1167 individuals presented for contrast-enhanced MR scans. Of 13 individuals on dialysis, 2 did not report renal disease. Of 1154 individuals not on dialysis, 25 had an eGFR <30 mL/min/1.73 m2 (95% CI 1.41%–3.18%). Of these 25, 13 did and 12 did not report renal disease. The sensitivity of the questionnaire for identifying patients with an eGFR <30 mL/min/1.73 m2 was 63.2%. POC eGFR estimations identified a prevalence of 2.17% (95% CI: 1.41%–3.18%) of the total individuals not on dialysis, with an eGFR <30 mL/min/1.73 m2. Patients who denied kidney dysfunction had a 1.08% (95% CI: 0.56%–1.88%) posttest probability of having an eGFR <30 mL/min/1.73 m2.
POC eGFR testing identified a significant number of individuals with renal dysfunction not found by the pre-MR imaging questionnaire alone.
Estimated glomerular filtration rate (eGFR); gadolinium-based contrast agents (GBCAs); point-of-care (POC); nephrogenic systemic fibrosis (NSF); screening questionnaires
Patient Navigation (PN) is a method for addressing racial-ethnic and socioeconomically based disparities in cancer-related care. Patient navigators provide logistic and emotional support to underserved patients to facilitate successful completion of diagnostic and treatment care. Yet, little is known about patient satisfaction with the relationship with a navigator due to a dearth of instruments measuring satisfaction.
To validate the Patient Satisfaction with Interpersonal Relationship with Navigator (PSN-I) measure for patients undergoing diagnostic and/or therapeutic cancer care.
We administered the PSN-I to 783 participants from the nine different sites of the National Cancer Institute sponsored Patient Navigation Research Program. We evaluated the latent structure and internal consistency of the PSN-I using principal components analysis (PCA) and Cronbach coefficient alpha (α) respectively. We used correlation analyses to examine divergence and convergence of the PSN-I with the Patient Satisfaction with Cancer-Related Care (PSCC), the Rapid Estimate of Adult Literacy in Medicine (REALM) Long Form, and patients’ demographics.
The PCA revealed a coherent set of items that explicates 76.6% of the variance in PSN-I. Reliability assessment revealed high internal consistency (α ranging from 0.95 to 0.96). The PSN-I had good face validity, as well as convergent and divergent validities as indicated by moderate correlations with score on the PSCC (all ps < 0.0001) and non-significant correlations with primary language, marital status, and scores on the REALM-Long Form (all ps > 0.05).
The PSN-I is a valid and suitable measure of satisfaction with a patient navigator for the present sample.
Prostate cancer disproportionately affects low-income and minority men. This study evaluates the impact of a patient navigation intervention on timeliness of diagnostic resolution and treatment initiation among veterans with an abnormal prostate cancer screen.
Participants were enrolled between 2006 and 2010. The intervention involved a social worker and lay health worker navigation team that assisted patients in overcoming barriers to care. For navigated (n = 245) versus control (n = 245) participants, we evaluated rates of diagnostic resolution and treatment and adjusted for race, age, and Gleason score.
Of 490 participants, 68% were African American, 47% were ≥ 65 years old, and 35% had cancer. Among those with an abnormal screen, navigation did not have a significant effect on time to diagnostic resolution compared to controls (median days of 97 versus 111; adj. HR 1.17, 95% CI, 0.96-1.43, p = 0.12). On analysis of the period beyond 80 days, navigated men reached resolution faster than controls (median of 151 days versus 190 days; adj. HR 1.41, 95% CI, 1.07-1.86, p = 0.01). Among those with cancer, navigation did not have a significant effect on time to treatment initiation compared to controls (median of 93 days versus 87 days; adj. HR 1.15, 95% CI, 0.82-1.62, p = 0.41).
Our navigation program did not significantly impact the overall time to resolution or treatment for men with prostate cancer compared to controls. The utility of navigation programs may extend beyond targeted navigation times, however, and future studies focusing on other outcomes measures are therefore needed.
Analysis of bisphosphonate-associated acute kidney injury reports for cancer cases within FDA's Adverse Events and Reporting System failed to demonstrate a significant safety signal, an unexpected finding given prior preclinical and clinical findings that suggested a causal association between BPs and AKI.
To determine whether acute kidney injury (AKI) is identified within the US Food and Drug Administration's Adverse Events and Reporting System (FDA AERS) as an adverse event resulting from bisphosphonate (BP) use in cancer therapy.
A search of the FDA AERS records from January 1998 through June 2009 was performed; search terms were “renal problems” and all drug names for BPs. The search resulted in 2,091 reports. We analyzed for signals of disproportional association by calculating the proportional reporting ratio for zoledronic acid (ZOL) and pamidronate. Literature review of BP-associated renal injury within the cancer setting was conducted.
Four hundred eighty cases of BP-associated acute kidney injury (AKI) were identified in patients with cancer. Two hundred ninety-eight patients (56%) were female; mean age was 66 ± 10 years. Multiple myeloma (n = 220, 46%), breast cancer (n = 98, 20%), and prostate cancer (n = 24, 5%) were identified. Agents included ZOL (n = 411, 87.5%), pamidronate (n = 8, 17%), and alendronate (n = 36, 2%). Outcomes included hospitalization (n = 304, 63.3%) and death (n = 68, 14%). The proportional reporting ratio for ZOL was 1.22 (95% CI, 1.13 to 1.32) and for pamidronate was 1.55 (95% CI, 1.25 to 1.65), reflecting a nonsignificant safety signal for both drugs.
AKI was identified in BP cancer clinical trials, although a safety signal for BPs and AKI within the FDA AERS was not detected. Our findings may be attributed, in part, to clinicians who believe that AKI occurs infrequently; ascribe the AKI to underlying premorbid disease, therapy, or cancer progression; or consider that AKI is a known adverse drug reaction of BPs and thus under-report AKI to the AERS.
The authors reviewed FDA and manufacturer responses to a citizen petition filed to address thalidomide safety issues and concluded that new approaches addressing off-label safety are needed.
Pharmaceutical safety is a public health issue. In 2005, the Connecticut Attorney General (AG) raised concerns over adverse drug reactions in off-label settings, noting that thalidomide was approved to treat a rare illness, but more than 90% of its use was off label. A hematologist had reported thalidomide with doxorubicin or dexamethasone was associated with venous thromboembolism (VTE) rates of 25%. We review US Food and Drug Administration (FDA) and manufacturer responses to a citizen petition filed to address these thalidomide safety issues.
The AG petitioned the FDA requesting thalidomide-related safety actions. Coincidentally, the manufacturer submitted a supplemental New Drug Approval (sNDA), requesting approval to treat multiple myeloma with thalidomide-dexamethasone. FDA safety officers reviewed the petition and the literature and noted that VTE risks with thalidomide were not appropriately addressed in the existing package insert. In the sNDA application, the manufacturer reported thalidomide-associated toxicities for multiple myeloma were primarily somnolence and neurotoxicity, and a proposed package insert did not focus on VTE risks. In October, the FDA informed the Oncology Drug Division that VTE risks with thalidomide were poorly addressed in the existing label. After reviewing this memorandum, an Oncology Drug Division reviewer informed the manufacturer that approval of the sNDA would be delayed until several thalidomide-associated VTE safety actions, including revisions of the package insert, were implemented. The manufacturer and FDA agreed on these actions, and the sNDA was approved.
New approaches addressing off-label safety are needed. The conditions that facilitated the successful response to this citizen petition are uncommon.
Individuals with type II diabetes have an increased risk of cancer diagnosis (relative risk [RR]=1.12–2.50) and mortality (RR=1.4) compared to normoglycemic individuals. Biologic mechanisms, including mitogenic effects of insulin, hyperglycemia, and increased oxidative stress, as well as behavioral factors (eg, difficulty managing the comorbidity) may explain the elevated risk. To investigate the effects of the comorbidity on disease management, the authors compared diabetes education utilization in individuals with diabetes-cancer co-morbidity to utilization by individuals with diabetes in the absence of cancer. The effect of diabetes education on outcomes was further assessed in the subset of individuals with diabetes–cancer comorbidity. Administrative claims data were used for this analysis. The study population included individuals >60 years of age and members of both commercial and Medicare Advantage health plans from a private national database of payer data, but excluded Medicare fee for service and Medicaid patients. Most of these individuals were eligible to receive reimbursement for diabetes education. Diabetes education utilization was identified using procedure codes. Outcomes were assessed for a 3-year time period. There was little difference in diabetes education utilization between individuals with diabetes in the absence of cancer (3.8% utilization) and those with diabetes–cancer comorbidity (3.5% utilization). Individuals who receive diabetes education are more likely to have multiple HbA1c tests per year, fewer emergency department visits, fewer hospital admissions, and lower care-associated costs (except for outpatient and pharmacy averages). When diabetes coexists with cancer, management of diabetes often lags, making diabetes education an imperative. (Population Health Management 2013;16:53–57.
Thrombotic thrombocytopenic purpura (TTP) is a fulminant disease characterized by platelet aggregates, thrombocytopenia, renal insufficiency, neurologic changes, and mechanical injury to erythrocytes. Most idiopathic cases of TTP are characterized by a deficiency of ADAMTS13 (a disintegrin and metalloprotease, with thrombospondin-1-like domains) metalloprotease activity. Ironically, use of anti-platelet agents, the thienopyridine derivates clopidogrel and ticlopidine, is associated with drug induced TTP. Data were abstracted from a systematic review of English-language literature for thienopyridine-associated TTP identified in MEDLINE, EMBASE, the public website of the Food and Drug Administration, and abstracts from national scientific conferences from 1991 to April 2008. Ticlopidine and clopidogrel are the two most common drugs associated with TTP in FDA safety databases. Epidemiological studies identify recent initiation of anti-platelet agents as the most common risk factor associated with risks of developing TTP. Laboratory studies indicate that most cases of thienopyridine-associated TTP involve an antibody to ADAMTS13 metalloprotease, present with severe thrombocytopenia, and respond to therapeutic plasma exchange (TPE); a minority of thienopyridine-associated TTP presents with severe renal insufficiency, involves direct endothelial cell damage, and is less responsive to TPE. The evaluation of this potentially fatal drug toxicity can serve as a template for future efforts to comprehensively characterize other severe adverse drug reactions.
drug-associated TTP; epidemiology; ADAMTS13
Patient navigation programs have been launched nationwide in an attempt to reduce racial/ethnic and socio-demographic disparities in cancer care, but few have evaluated outcomes in the prostate cancer setting. The National Cancer Institute-funded Chicago Patient Navigation Research Program (C-PNRP) aims to implement and evaluate the efficacy of a patient navigation intervention for predominantly low-income minority patients with an abnormal prostate cancer screening test at a Veterans Affairs (VA) hospital in Chicago.
From 2006 through 2010, C-PNRP implemented a quasi-experimental intervention whereby trained social worker and lay health navigators worked with veterans with an abnormal prostate screen to proactively identify and resolve personal and systems barriers to care. Men were enrolled at a VA urology clinic and were selected to receive navigated versus usual care based on clinic day. Patient navigators performed activities to facilitate timely follow-up such as appointment reminders, transportation coordination, cancer education, scheduling assistance, and social support as needed. Primary outcome measures included time (days) from abnormal screening to diagnosis and time from diagnosis to treatment initiation. Secondary outcomes included psychosocial and demographic predictors of non-compliance and patient satisfaction. Dates of screening, follow-up visits, and treatment were obtained through chart audit, and questionnaires were administered at baseline, after diagnosis, and after treatment initiation. At the VA, 546 patients were enrolled in the study (245 in the navigated arm, 245 in the records-based control arm, and 56 in a subsample of surveyed control subjects).
Given increasing concerns about balancing better health outcomes with lower costs, careful examination of interventions aimed at reducing healthcare disparities attain critical importance. While analysis of the C-PNRP data is underway, the design of this patient navigation intervention will inform other patient navigation programs addressing strategies to improve prostate cancer outcomes among vulnerable populations.
Patient navigation; Prostate cancer; Cancer health disparities; Veterans
Wider use of FDA anti-counterfeit initiatives, limiting pharmaceutical suppliers to reputable distributors, and educating providers and patients about signs of counterfeit drugs can improve the safety of cancer pharmaceuticals.
Counterfeit pharmaceuticals pose risks domestically. Because of their cost, cancer pharmaceuticals are vulnerable. We review findings from a domestic counterfeiting episode involving erythropoietin and outline anticounterfeiting recommendations for policy makers, patients, and health care professionals.
Materials and Methods:
Information was obtained on patients who received counterfeit erythropoietin, its distribution, and criminal investigations into counterfeiting networks. Interview sources included a physician, an attorney, employees of the Florida Department of Health and Human Services and the US Food and Drug Administration's (FDA) Office of Criminal Investigation, manufacturers, and wholesalers. Other sources included the book “Dangerous Doses,” LexisNexis (search terms “counterfeit” and “erythropoietin”) and the FDA database.
Counterfeit product consisted of 2,000 U vials with counterfeit labels denoting 40,000 U. The counterfeiters, in collaboration with a Miami pharmacy, purchased 110,000 erythropoietin 2,000 U vials and affixed counterfeit labels to each vial. Products were then sold via the pharmaceutical “gray market” to wholesalers, then pharmacy chains. Investigations by Florida government officials implicated 17 persons, all of whom were found guilty of trafficking in counterfeit pharmaceuticals. Despite the large size of the operation, the FDA received reports of only 12 patients who had received counterfeit erythropoietin and detailed information for only two individuals. A 17-year-old liver transplant recipient and a 61-year-old patient with breast cancer experienced loss of efficacy after receiving counterfeit erythropoietin.
Wider use of FDA anticounterfeit initiatives, limiting pharmaceutical suppliers to reputable distributors, and educating providers and patients about signs of counterfeit drugs can improve the safety of cancer pharmaceuticals.
Serious adverse drug event (sADE) reporting to Institutional Review Boards (IRB) is essential to ensure pharmaceutical safety. However, the quality of these reports has not been studied. Safety reports are especially important for cancer drugs that receive accelerated Food and Drug Administration approval, like imatinib, as preapproval experience with these drugs is limited. We evaluated the quality, accuracy, and completeness of sADE reports submitted to an IRB.
sADE reports submitted to an IRB from 14 clinical trials with imatinib were reviewed. Structured case report forms, containing detailed clinical data fields and a validated causality assessment instrument, were developed. Two forms were generated for each ADE, the first populated with data abstracted from the IRB reports, and the second populated with data from the corresponding clinical record. Completeness and causality assessments were evaluated for each of the two sources, and then compared. Accuracy (concordance between sources) was also assessed.
Of 115 sADEs reported for 177 cancer patients to the IRB, overall completeness of adverse event descriptions was 2.4-fold greater for structured case report forms populated with information from the clinical record versus the corresponding forms from IRB reports (95.0% versus 40.3%, P < 0.05). Information supporting causality assessments was recorded 3.5-fold more often in primary data sources versus IRB adverse event descriptions (93% versus 26%, P < 0.05). Some key clinical information was discrepant between the two sources.
The use of structured syndrome-specific case report forms could enhance the quality of reporting to IRBs, thereby improving the safety of pharmaceuticals administered to cancer patients.
Aromatase inhibitors (AIs) have been recently associated with hip fractures. We present a case series of breast cancer survivors and a systematic review of bone health care in breast cancer.
We completed clinical assessments and bone density testing (BMD) of hip fractures from January 2005–December 2008. Pre-fracture and 12-month functional status was obtained. Systematic review included case reports and review of MEDLINE, PubMed, EMBASE, and Food and Drug Administration Adverse Event Reporting System (FDA AERS) from January 1998–December 2008 (search terms: breast cancer, bone loss, osteopenia, osteoporosis, malignancy, cancer treatment, menopause, adriamycin, cytoxan, tamoxifen, and AIs).
Median age was 53.5 years; five women had osteopenia, one osteoporosis. Five cases were ER (+), and received surgery, XRT chemotherapy, and anastrozole. Functional decline was noted at 12 months, with difficulty in performing heavy housekeeping, climbing stairs and shopping. The FDA AERS database included 228 cases of fractures associated with breast cancer therapy; 77/228 (29.4%) were hip or femur fractures. Among mid-life women under the age of 64 years there were 78 fractures; 15/228 (19%) were hip and femur fractures. AIs were the most common drug class associated with fractures (n=149, 65%).
CTIBL results in hip fractures among mid-life women with breast cancer. Hip fractures occur at younger ages and higher BMD than expected for patients in this age group without breast cancer. Hip fractures result in considerable functional decline. Greater awareness of this adverse drug effect is needed.
aromatase inhibitors; menopause; osteopenia; osteoporosis; fracture prevention; cancer treatment induced bone loss
We sought to describe clinical and laboratory findings for a large cohort of patients with thienopyridine-associated thrombotic thrombocytopenic purpura (TTP).
The thienopyridine derivatives, ticlopidine and clopidogrel, are the 2 most common drugs associated with TTP in databases maintained by the U.S. Food and Drug Administration (FDA).
Clinical reports of TTP associated with clopidogrel and ticlopidine were identified from medical records, published case reports, and FDA case reports (n = 128). Duration of thienopyridine exposure, clinical and laboratory findings, and survival were recorded. ADAMTS13 activity (n = 39) and inhibitor (n = 30) were measured for a subset of individuals.
Compared with clopidogrel-associated TTP cases (n = 35), ticlopidine-associated TTP cases (n = 93) were more likely to have received more than 2 weeks of drug (90% vs. 26%), to be severely thrombocytopenic (84% vs. 60%), and to have normal renal function (72% vs. 45%) (p < 0.01 for each). Compared with TTP patients with ADAMTS13 activity >15% (n = 13), TTP patients with severely deficient ADAMTS13 activity (n = 26) were more likely to have received ticlopidine (92.3% vs. 46.2%, p < 0.003). Among patients who developed TTP >2 weeks after thienopyridine, therapeutic plasma exchange (TPE) increased likelihood of survival (84% vs. 38%, p < 0.05). Among patients who developed TTP within 2 weeks of starting thienopyridines, survival was 77% with TPE and 78% without.
Thrombotic thrombocytopenic purpura is a rare complication of thienopyridine treatment. This drug toxicity appears to occur by 2 different mechanistic pathways, characterized primarily by time of onset before versus after 2 weeks of thienopyridine administration. If TTP occurs after 2 weeks of ticlopidine or clopidogrel therapy, therapeutic plasma exchange must be promptly instituted to enhance likelihood of survival.
Patient navigators--individuals who assist patients through the healthcare system to improve access to and understanding of their health and health care—are increasingly utilized for underserved individuals at risk for or with cancer. Navigation programs can improve access, but it is unclear whether they improve the efficiency and efficacy of cancer diagnostic and therapeutic services at a reasonable cost, such that they would be considered cost effective.
We outline a conceptual model for evaluating the cost effectiveness of cancer navigation programs. We describe how this model is being applied to the Patient Navigation Research Program (PNRP), a multi-center study supported by the National Cancer Institute’s Center to Reduce Cancer Health Disparities.
The PNRP is testing navigation interventions which aim to reduce time to delivery of quality cancer care (non-cancer resolution or cancer diagnosis and treatment) after identification of a screening abnormality. Examples of challenges to evaluating cost effectiveness of navigation programs include the heterogeneity of navigation programs, the sometimes distant relationship between navigation programs and outcome of interest (e.g., improving access to prompt diagnostic resolution and life years gained) and accounting for factors in underserved populations that may influence both access to services and outcomes. In this article, we discuss several strategies for addressing these barriers.
Evaluating the costs and impact of navigation will require some novel methods, but will be critical in recommendations about dissemination of navigation programs.
cancer; navigator; cost effectiveness; modeling
Colorectal cancer (CRC) screening remains underutilized in the United States. Prior studies reporting the cost effectiveness of randomized interventions to improve CRC screening have not been replicated in the setting of small physician practices. We recently conducted a randomized trial evaluating an academic detailing intervention in 264 small practices in geographically diverse New York City communities. The objective of this secondary analysis is to assess the cost effectiveness of this intervention.
A total of 264 physician offices were randomly assigned to usual care or to a series of visits from trained physician educators. CRC screening rates were measured at baseline and 12 months. The intervention costs were measured and the incremental cost-effectiveness ratio (ICER) was derived. Sensitivity analyses were based on varying cost and effectiveness estimates.
Academic detailing was associated with a 7% increase in CRC screening with colonoscopy. The total intervention cost was $147,865, and the ICER was $21,124 per percentage point increase in CRC screening rate. Sensitivity analyses that varied the costs of the intervention and the average medical practice size were associated with ICERs ranging from $13,631 to $36,109 per percentage point increase in CRC screening rates.
A comprehensive, multicomponent academic detailing intervention conducted in small practices in metropolitan New York was clinically effective in improving CRC screening rates, but was not cost effective.
In April 2009, the FDA retracted a warning asserting that ceftriaxone and intravenous calcium products should not be coadministered to any patient to prevent precipitation events leading to end-organ damage. Following that announcement, we sought to evaluate if the retraction was justified. A search of the FDA Adverse Event Reporting System was conducted to identify any ceftriaxone-calcium interactions that resulted in serious adverse drug events. Ceftazidime-calcium was used as a comparator agent. One hundred four events with ceftriaxone-calcium and 99 events with ceftazidime-calcium were identified. Adverse drug events were recorded according to the listed description of drug involvement (primary or secondary suspect) and were interpreted as probable, possible, unlikely, or unrelated. For ceftriaxone-calcium-related adverse events, 7.7% and 20.2% of the events were classified as probable and possible for embolism, respectively. Ceftazidime-calcium resulted in fewer probable embolic events (4%) but more possible embolic events (30.3%). Among cases that considered ceftriaxone or ceftazidime and calcium as the primary or secondary drug, one case was classified as a probable embolic event. That patient received ceftriaxone-calcium and died, although an attribution of causality was not possible. Our analysis suggests a lack of support for the occurrence of ceftriaxone-calcium precipitation events in adults. The results of the current analysis reinforce the revised FDA recommendations suggesting that patients >28 days old may receive ceftriaxone and calcium sequentially and provide a transparent and reproducible methodology for such evaluations.
Accelerated approval (AA) was initiated by the US Food and Drug Administration (FDA) to shorten development times of drugs for serious medical illnesses. Sponsors must confirm efficacy in postapproval trials. Confronted with several drugs that received AA on the basis of phase II trials and for which confirmatory trials were incomplete, FDA officials have encouraged sponsors to design AA applications on the basis of interim analyses of phase III trials.
We reviewed data on orphan drug status, development time, safety, and status of confirmatory trials of AAs and regular FDA approvals of new molecular entities (NMEs) for oncology indications since 1995.
Median development times for AA NMEs (n = 19 drugs) and regular-approval oncology NMEs (n = 32 drugs) were 7.3 and 7.2 years, respectively. Phase III trials supported efficacy for 75% of regular-approval versus 26% of AA NMEs and for 73% of non–orphan versus 45% of orphan drug approvals. AA accounted for 78% of approvals for oncology NMEs between 2001 and 2003 but accounted for 32% in more recent years. Among AA NMEs, confirmatory trials were nine-fold less likely to be completed for orphan drug versus non–orphan drug indications. Postapproval, black box warnings were added to labels for four oncology NMEs (17%) that had received AA and for two oncology NMEs (9%) that had received regular approval.
AA oncology NMEs are safe and effective, although development times are not accelerated. A return to endorsing phase II trial designs for AA for oncology NMEs, particularly for orphan drug indications, may facilitate timely FDA approval of novel cancer drugs.
The authors explain why physicians should refrain from ordering MRIs for patients with renal dysfunction unless the test is essential to provide diagnostic information. A possibly class-wide toxicity from the contrast agent gadolinium has been reported.
Background and objective
The antiretroviral nevirapine can cause severe hepatotoxicity when used ‘off-label’ for preventing mother-to-child HIV transmission (PMTCT), newborn post-exposure prophylaxis and for pre- and post-exposure prophylaxis among non-HIV-infected individuals. We describe the incidence of hepatotoxicity with short- versus long-course nevirapine-containing regimens in these groups.
We reviewed hepatotoxicity cases among non-HIV-infected individuals and HIV-infected pregnant women and their offspring receiving short- (≤4 days) versus long-course (≥5 days) nevirapine prophylaxis. Sources included adverse event reports from pharmaceutical manufacturers and the US FDA, reports from peer-reviewed journals/scientific meetings and the Research on Adverse Drug events And Reports (RADAR) project. Hepatotoxicity was scored using the AIDS Clinical Trial Group criteria.
Toxicity data for 8216 patients treated with nevirapine-containing regimens were reviewed. Among 402 non-HIV-infected individuals receiving short- (n = 251) or long-course (n = 151) nevirapine, rates of grade 1–2 hepatotoxicity were 1.99%versus 5.30%, respectively, and rates of grade 3–4 hepatotoxicity were 0.00% versus 13.25%, respectively (p < 0.001 for both comparisons). Among 4740 HIV-infected pregnant women receiving short- (n = 3031) versus long-course (n = 1709) nevirapine, rates of grade 1–2 hepatotoxicity were 0.62% and 7.04%, respectively, and rates of grade 3–4 hepatotoxicity were 0.23% versus 4.39%, respectively (p < 0.001 for both comparisons). The rates of grade 3–4 hepatotoxicity among 3074 neonates of nevirapine-exposed HIV-infected pregnant women were 0.8% for those receiving short-course (n = 2801) versus 1.1%for those receiving long-course (n = 273) therapy (p < 0.72).
Therapy duration appears to significantly predict nevirapine hepatotoxicity. Short-course nevirapine for HIV prophylaxis is associated with fewer hepatotoxic reactions for non-HIV-infected individuals or pregnant HIV-infected women and their offspring, but administration of prophylactic nevirapine for ≥2 weeks appears to be associated with high rates of hepatotoxicity among non-HIV-infected individuals and HIV-infected pregnant mothers. When full highly active antiretroviral therapy (HAART) regimens are not available, single-dose nevirapine plus short-course nucleoside reverse transcriptase inhibitors to decrease the development of HIV viral resistance is an essential therapeutic option for PMTCT and these data support the safety of single-dose nevirapine in this setting.
Cost-related medication non-adherence may be influenced by patients' perceived importance of their medications. This exploratory study addresses three related but distinct questions: Do patients perceive different levels of importance among their medications? What factors influence perceptions of medication importance? Is perceived importance associated with medications' worth, and does expense impact that association?
Study participants included individuals aged 60 and older who were taking three or more prescription drugs. Semi-structured, in-person interviews were conducted to measure how patients rated their medications in terms of importance, expense, and worth. Factors that influence medication importance were identified using qualitative analysis. Ordinal logistic regression analyses were employed to examine the association between perceived importance and worth of medications, and the impact of expense on that association.
Among 143 prescription drugs reported among 20 participants, the weighted mean rating of medication importance was 8.2 (SD=1.04) on a scale from 0 (not important at all) to 10 (most important). Of all medications, 38% were considered expensive. The weighted mean rating of worth was 8.4 (SD=1.46) on a scale from 0 (not worth it at all) to 10 (definitely worth it). Three major factors influenced medication importance: drug-related (characteristics, indications, effects, and alternatives); patient-related (knowledge, attitudes, and health); and external (the media, healthcare and family caregivers, and peers). Regression analyses showed an association between perceived importance and worth for inexpensive medications (OR=2.23; p=0.002) and an even greater association between perceived importance and worth for expensive medications (OR=4.29; p<0.001).
This study provides preliminary evidence that elderly patients perceive different levels of importance among their medications based on factors beyond clinical efficacy and their perception of importance influences how they perceive their medications' worth, especially for medications of high costs. Understanding how patients perceive medication importance may help develop interventions to reduce cost-related non-adherence.
medication prioritization; essential drugs; nonadherence; medication adherence
Since 1988, millions of patients have received epoetin products intravenously (IV) and subcutaneously. In 1998, epoetin-associated pure red cell aplasia (PRCA) was first reported and causation was attributed to formulations without human serum albumin (HSA), subcutaneous administration, and uncoated rubber stoppers.
STUDY DESIGN AND METHODS
Data on erythropoietin (EPO)-associated PRCA were obtained from the Food and Drug Administration (FDA), regulatory authorities in other countries, and the manufacturers of epoetin alfa, epoetin beta, and darbepoetin. The data included information on numbers of PRCA cases and estimated exposure-adjusted incidence rates by EPO product, anemia etiology, administration route, country of PRCA identification, and date reported.
In 1999, academicians in Paris identified 12 EPO-treated patients with antibody-mediated PRCA; 11 of these patients were on hemodialysis and had received subcutaneous Eprex (Johnson & Johnson). In 2002, authorities in Europe, Australia, Singapore, and Canada mandated Eprex by IV route to hemodialysis patients, and the relevant manufacturers added Teflon coating to prefilled syringes of Eprex; PRCA cases subsequently decreased by 90 percent. By 2003, 180 Eprex-associated PRCA cases were identified in Europe, Canada, Australia, and Asia, despite improvements in handling. Since 2002, FDA safety databases include information on 59 new cases of antibody-associated PRCA, primarily associated with subcutaneous epoetin alfa and darbepoetin that does not contain HSA.
Independent actions by regulatory authorities, manufacturers, and academic researchers identified significant numbers of PRCA cases between 1998 and 2003 and characterized the probable etiology. Today, antibody-mediated PRCA is an infrequent class toxicity occurring among some hemodialysis patients on EPOs.
Although amiodarone is the most commonly prescribed antiarrhythmic drug, its use is limited by serious toxicities, including optic neuropathy. Current reports of amiodarone associated optic neuropathy identified from the Food and Drug Administration's Adverse Event Reporting System (FDA-AERS) and published case reports were reviewed. A total of 296 reports were identified: 214 from AERS, 59 from published case reports, and 23 from adverse events reports for patients enrolled in clinical trials. Mean duration of amiodarone therapy before vision loss was 9 months (range 1-84 months). Insidious onset of amiodarone associated optic neuropathy (44%) was the most common presentation, and nearly one-third were asymptomatic. Optic disc edema was present in 85% of cases. Following drug cessation, 58% had improved visual acuity, 21% were unchanged, and 21% had further decreased visual acuity. Legal blindness (< 20/200) was noted in at least one eye in 20% of cases. Close ophthalmologic surveillance of patients during the tenure of amiodarone administration is warranted.
amiodarone; vision loss; optic neuropathy